This invention relates to water purification systems, and in particular, to a cleaning system and method for periodically flushing reverse osmosis water purification systems to rid the systems of decontaminants and other pollutants that build up during use.
Osmosis is a process that occurs when two similar solutions come into contact across a semi-permeable membrane acting as a barrier to the solute molecules, but permitting the solvent molecules to pass across. When one of the solutions has a higher concentration of solute than the other, the solvent will pass from the weaker concentration solution ("less osmotic active") solution to the higher concentration solution ("higher osmotic active") until the concentration of solute to solvent is the same on both sides. Reverse osmosis reverses this process by applying pressure to the higher osmotic active solution, forcing the solvent to go through the membrane to the less active solution thus resulting in a continuously more pure solvent, i.e., the "clean R/O product". Reverse osmosis systems ("R/O systems") have wide spread application ranging from use in desalination of salt water systems to kidney dialysis apparatus.
During the reverse osmosis process, the membranes and other operation components of the R/O system, including the component containing the semi-permeable membrane (the "R/O unit"), slowly become contaminated and it is necessary to periodically clean the system including the membrane. Numerous cleaning techniques have been employed as disclosed by U.S. Pat. Nos. 3,835,756, 4,7565,906, and 5,393,502. The state of the art is perhaps best described by reference to U.S. Pat. No. 4,784,771 issued Nov. 15, 1988 to Ronald L. Wathen et. al. and assigned then to Environmental Water Technologies. While effective, the system of this patent is representative of the complex nature of systems presently used to clean R/O systems of contaminants.
An important object of the present invention is to provide a simple but effective system for the cleaning of R/O systems.
It is still another important object of the present invention to provide for a cleaning system that can be readily attached or incorporated into a R/O system, resulting in the cleaning of contaminant from the system in a self-controlling manner which minimizes oversee of the cleaning cycle.
Other important advantages will become readily apparent following a reading of the following in reference to the FIGS.